Lithium battery integrated temperature control system based on waste heat recovery

Abstract

The invention relates to the technical field of batteries, and discloses a lithium battery integrated temperature control system based on waste heat recovery, which comprises a water cooling module, a waste heat recovery module, a preheating module and a mode switching module. The water cooling module dissipates heat of the lithium battery pack and outputs a cooling medium with waste heat; the mode switching module can be manually or automatically switched between a preheating state enabling a cooling medium to flow to the waste heat recovery module and a heat dissipation state enabling the cooling medium to bypass the waste heat recovery module. The waste heat recovery module recovers waste heat in the cooling medium through the plate heat exchanger; the preheating module preheats the lithium battery pack through the recycled waste heat. According to the method, system waste heat is preferentially used for preheating the low-temperature battery, and the electric heater is started for auxiliary heating only when the waste heat is insufficient. The system is simple in structure, high in reliability, excellent in heat exchange efficiency, capable of remarkably reducing the low-temperature preheating energy consumption of the lithium battery and suitable for green energy projects such as new energy automobiles and energy storage power stations.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to an integrated temperature control system for lithium batteries based on waste heat recovery. Background Technology

[0002] Amid the global wave of energy transition towards clean and low-carbon energy, green energy projects such as new energy vehicles, large-scale energy storage power stations, and distributed photovoltaic systems with supporting energy storage have experienced explosive growth. These projects aim to "efficiently utilize clean energy and reduce carbon emissions throughout the entire lifecycle." However, in actual industrialization, the waste of waste heat from the cooling systems of core equipment and the low-temperature performance degradation of lithium batteries compound each other, reducing overall energy utilization efficiency and increasing operating costs and failure risks. This has become a key bottleneck restricting the large-scale promotion of green energy.

[0003] In the equipment system of green energy projects, the cooling system is the "lifeline" for the stable operation of core components. New energy vehicle drive motors (100-200kW) and electronic control systems continuously generate heat during operation. Temperatures exceeding 120℃ will accelerate the aging of the motor insulation layer (reducing lifespan by more than 30%) and may also burn out the electronic control IGBT module, resulting in repair costs of tens of thousands of yuan. Similarly, the energy storage converters (PCS) in large energy storage power stations also accumulate heat during high-frequency charging and discharging (especially at peak power). Cooling systems are required to control the temperature between 40-60℃; otherwise, the energy conversion efficiency will decrease by 5%-10%, affecting the power station's profitability.

[0004] Currently, most cooling systems of this type use water cooling, circulating an ethylene glycol aqueous solution (antifreeze, excellent thermal conductivity) to absorb heat before dissipating it from the outlet. Industry tests show that during normal operation of a new energy vehicle, the coolant temperature at the water-cooled outlet is 60-80℃; when the energy storage power station is operating at full load, the outlet temperature is 50-70℃. However, in existing technologies, this hot coolant is only cooled by radiators and fans, with the heat directly discharged into the environment without being recovered. Specifically, a new energy vehicle with a range of 500km, after a full charge, dissipates approximately 8-12MJ of heat from its cooling system during urban driving, which is 1.8 times the amount of heat required to preheat a lithium battery from -10℃ to 15℃ (requiring 5MJ); a 1MW / 2MWh energy storage power station wastes 30-40kWh of waste heat per day in its cooling system, equivalent to the daily electricity consumption of 20 households (average daily electricity consumption of 1.5-2kWh). This "passive cooling, no waste heat recovery" model is not only wasteful of energy but also contradicts the "increasing supply and reducing consumption" principle of green energy.

[0005] As a core energy storage component, lithium batteries are extremely sensitive to temperature in terms of electrochemical performance. Their charging and discharging essentially involves the insertion and extraction of lithium ions between the positive and negative electrodes. Low temperatures reduce the ionic conductivity of the electrolyte, inhibiting lithium ion migration. Below 0°C, the ionic conductivity of lithium batteries drops by more than 50%, causing a sharp decline in charging efficiency: in winter at -10°C, the charging time for lithium batteries in new energy vehicles is 2-3 times longer than at room temperature (25°C), resulting in a 30%-50% reduction in driving range, requiring frequent recharging for long-distance travel; at extreme low temperatures of -20°C, some lithium iron phosphate batteries may even fail to charge or discharge, causing vehicle breakdowns or grid connection problems, resulting in serious losses and potential hazards.

[0006] To address this issue, existing technologies often employ additional electric heating devices (resistance wires, PTC heaters, etc.) to preheat lithium batteries, but this requires significant power consumption: When starting a new energy vehicle in winter, the electric heating power is 3-5kW, and a single preheating session (15-20 minutes) consumes 1-1.5kWh, further reducing the driving range by 20-30km. In low-temperature environments, electric heating in energy storage power stations accounts for 5%-8% of total daily power generation; a 100MW / 200MWh power station consumes 5-8MWh daily for electric heating, equivalent to the monthly electricity consumption of 50-80 households. This contradiction of "preserving performance while consuming energy" seriously violates the concept of green energy.

[0007] While the industry is exploring technologies that combine waste heat from cooling systems with lithium battery preheating, existing solutions have significant drawbacks. Some solutions use an automatic switching mode via a "temperature sensor + controller + solenoid valve": when the temperature is below 5℃, the waste heat channel is activated; when it is above 25℃, conventional cooling is switched on. However, this solution has three major problems: First, the cost is high. A set of automatic components (including high-precision sensors, PLC, and waterproof solenoid valves) costs approximately 800-1200 yuan, which is 8-12 times that of a manual solution (100 yuan), making it unacceptable for car manufacturers producing millions of vehicles or power plants with gigawatt-scale capacity. Second, the failure rate is high. The bumps and vibrations of new energy vehicles and the outdoor environment of power plants can easily cause sensor deviations (above ±3℃) and solenoid valve leaks. Data from a leading car manufacturer shows that the average annual failure rate of such devices is 18.7%, far exceeding the 5% threshold for traditional components. Third, maintenance is difficult. Troubleshooting requires specialized equipment, and repairs require disassembling multiple components, averaging 4 hours, which does not meet the requirements of "high reliability and low maintenance."

[0008] In summary, the waste of waste heat in cooling systems, the high energy consumption of low-temperature preheating of lithium batteries, and the reliance on automation and low efficiency of existing devices are common problems that urgently need to be solved in the industry. There is an urgent need to develop waste heat utilization devices that are simple in structure, do not require complex automation, and are highly efficient and low-cost, to recover waste heat for preheating lithium batteries and adapt to the development of green energy projects. Summary of the Invention

[0009] This invention provides an integrated temperature control system for lithium batteries based on waste heat recovery to solve the above-mentioned problems.

[0010] In a first aspect, the present invention provides an integrated temperature control system for lithium batteries based on waste heat recovery, comprising:

[0011] A water-cooling module is configured to dissipate heat from the lithium battery pack and output a cooling medium carrying the residual heat.

[0012] A waste heat recovery module, which is in fluid communication with the water cooling module, is configured to recover waste heat from the cooling medium;

[0013] A preheating module, thermally connected to the waste heat recovery module, and configured to preheat the lithium battery pack using the recovered waste heat; and

[0014] A mode switching module is disposed in the flow path between the water cooling module and the waste heat recovery module, and is configured to operablely switch between a first state in which the cooling medium flows to the waste heat recovery module and a second state in which the cooling medium bypasses the waste heat recovery module.

[0015] In one alternative implementation, the mode switching module includes a manually operated valve.

[0016] In one optional implementation, the water-cooling module includes:

[0017] A liquid cooling plate is configured to be in thermal contact with the lithium battery pack;

[0018] A circulating pump drives the cooling medium to circulate between the liquid-cooled plate and a storage container; and

[0019] An electric heater is provided for auxiliary heating of the cooling medium.

[0020] In one optional embodiment, the waste heat recovery module includes a plate heat exchanger having a first flow channel and a second flow channel that are isolated from each other. The first flow channel is in fluid communication with the water-cooled module, and the second flow channel is filled with a preheating medium and is in fluid communication with the preheating module.

[0021] In one optional implementation, the preheating module includes:

[0022] A preheating chamber, which covers at least a portion of the outer surface of the lithium battery pack; and

[0023] A thermally conductive interface layer is disposed between the preheating cavity and the lithium battery pack.

[0024] In one optional embodiment, a heat storage container is further provided between the second flow channel and the preheating cavity.

[0025] In one alternative implementation, a control unit is further included, the control unit being configured to:

[0026] Obtain the temperature information of the lithium battery pack;

[0027] Based on the temperature information, control the state switching of the mode switching module and / or control the start and stop of the electric heater in the water cooling module.

[0028] In an alternative implementation, the control unit is further configured to:

[0029] Obtain the temperature information of the cooling medium output by the water-cooling module;

[0030] The conditions for controlling the mode switching module to switch to the first state include: the temperature of the lithium battery pack is lower than a first preset threshold, and the temperature of the cooling medium is higher than a second preset threshold.

[0031] In an optional implementation, an optimization unit communicatively connected to the control unit is further included, the optimization unit being configured to:

[0032] Based on the operating parameters and / or environmental parameters of the lithium battery pack, an optimized instruction for adjusting the operating parameters of the water cooling module and / or the waste heat recovery module is output through a pre-trained neural network model.

[0033] The operating parameters include at least one of the following: the flow rate of the circulating pump, the power of the electric heater, and the operating parameters of the plate heat exchanger.

[0034] Secondly, the present invention also provides a lithium battery thermal management method, comprising:

[0035] The lithium battery pack is cooled by a water-cooling module, which generates a cooling medium that carries the residual heat.

[0036] Monitor the temperature of the lithium battery pack;

[0037] When the temperature of the lithium battery pack is lower than the preheating trigger temperature, the control mode switching module switches to the first state, guides the cooling medium to the waste heat recovery module to recover waste heat, and uses the recovered waste heat to preheat the lithium battery pack.

[0038] When the recovered waste heat is insufficient to raise the temperature of the lithium battery pack to the target temperature, the electric heater in the water-cooling module is activated to provide auxiliary heating to the cooling medium. Attached Figure Description

[0039] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of an integrated temperature control system for lithium batteries based on waste heat recovery, according to an embodiment of the present invention.

[0041] Explanation of reference numerals in the attached figures:

[0042] 11. Circulating pump; 12. Liquid cooling plate; 13. Electric heater; 14. Coolant tank;

[0043] 2. Lithium battery pack;

[0044] 3. Manually operated valve;

[0045] 4. Plate heat exchanger;

[0046] 5. Heat storage container;

[0047] 6. Smart switch. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] Amid the global wave of energy transition towards clean and low-carbon energy, green energy projects such as new energy vehicles, large-scale energy storage power stations, and distributed photovoltaic systems with supporting energy storage have experienced explosive growth. These projects aim to "efficiently utilize clean energy and reduce carbon emissions throughout the entire lifecycle." However, in actual industrialization, the waste of waste heat from the cooling systems of core equipment and the low-temperature performance degradation of lithium batteries compound each other, reducing overall energy utilization efficiency and increasing operating costs and failure risks. This has become a key bottleneck restricting the large-scale promotion of green energy.

[0050] In the equipment system of green energy projects, the cooling system is the "lifeline" for the stable operation of core components. New energy vehicle drive motors (100-200kW) and electronic control systems continuously generate heat during operation. Temperatures exceeding 120℃ will accelerate the aging of the motor insulation layer (reducing lifespan by more than 30%) and may also burn out the electronic control IGBT module, resulting in repair costs of tens of thousands of yuan. Similarly, the energy storage converters (PCS) in large energy storage power stations also accumulate heat during high-frequency charging and discharging (especially at peak power). Cooling systems are required to control the temperature between 40-60℃; otherwise, the energy conversion efficiency will decrease by 5%-10%, affecting the power station's profitability.

[0051] Currently, most cooling systems of this type use water cooling, circulating an ethylene glycol aqueous solution (antifreeze, excellent thermal conductivity) to absorb heat before dissipating it from the outlet. Industry tests show that during normal operation of a new energy vehicle, the coolant temperature at the water-cooled outlet is 60-80℃; when the energy storage power station is operating at full load, the outlet temperature is 50-70℃. However, in existing technologies, this hot coolant is only cooled by radiators and fans, with the heat directly discharged into the environment without being recovered. Specifically, a new energy vehicle with a range of 500km, after a full charge, dissipates approximately 8-12MJ of heat from its cooling system during urban driving, which is 1.8 times the amount of heat required to preheat a lithium battery from -10℃ to 15℃ (requiring 5MJ); a 1MW / 2MWh energy storage power station wastes 30-40kWh of waste heat per day in its cooling system, equivalent to the daily electricity consumption of 20 households (average daily electricity consumption of 1.5-2kWh). This "passive cooling, no waste heat recovery" model is not only wasteful of energy but also contradicts the "increasing supply and reducing consumption" principle of green energy.

[0052] As a core energy storage component, lithium batteries are extremely sensitive to temperature in terms of electrochemical performance. Their charging and discharging essentially involves the insertion and extraction of lithium ions between the positive and negative electrodes. Low temperatures reduce the ionic conductivity of the electrolyte, inhibiting lithium ion migration. Below 0°C, the ionic conductivity of lithium batteries drops by more than 50%, causing a sharp decline in charging efficiency: in winter at -10°C, the charging time for lithium batteries in new energy vehicles is 2-3 times longer than at room temperature (25°C), resulting in a 30%-50% reduction in driving range, requiring frequent recharging for long-distance travel; at extreme low temperatures of -20°C, some lithium iron phosphate batteries may even fail to charge or discharge, causing vehicle breakdowns or grid connection problems, resulting in serious losses and potential hazards.

[0053] To address this issue, existing technologies often employ additional electric heating devices (resistance wires, PTC heaters, etc.) to preheat lithium batteries, but this requires significant power consumption: When starting a new energy vehicle in winter, the electric heating power is 3-5kW, and a single preheating session (15-20 minutes) consumes 1-1.5kWh, further reducing the driving range by 20-30km. In low-temperature environments, electric heating in energy storage power stations accounts for 5%-8% of total daily power generation; a 100MW / 200MWh power station consumes 5-8MWh daily for electric heating, equivalent to the monthly electricity consumption of 50-80 households. This contradiction of "preserving performance while consuming energy" seriously violates the concept of green energy.

[0054] While the industry is exploring technologies that combine waste heat from cooling systems with lithium battery preheating, existing solutions have significant drawbacks. Some solutions use an automatic switching mode via a "temperature sensor + controller + solenoid valve": when the temperature is below 5℃, the waste heat channel is activated; when it is above 25℃, conventional cooling is switched on. However, this solution has three major problems: First, the cost is high. A set of automatic components (including high-precision sensors, PLC, and waterproof solenoid valves) costs approximately 800-1200 yuan, which is 8-12 times that of a manual solution (100 yuan), making it unacceptable for car manufacturers producing millions of vehicles or power plants with gigawatt-scale capacity. Second, the failure rate is high. The bumps and vibrations of new energy vehicles and the outdoor environment of power plants can easily cause sensor deviations (above ±3℃) and solenoid valve leaks. Data from a leading car manufacturer shows that the average annual failure rate of such devices is 18.7%, far exceeding the 5% threshold for traditional components. Third, maintenance is difficult. Troubleshooting requires specialized equipment, and repairs require disassembling multiple components, averaging 4 hours, which does not meet the requirements of "high reliability and low maintenance."

[0055] In summary, the waste of waste heat in cooling systems, the high energy consumption of low-temperature preheating of lithium batteries, and the reliance on automation and low efficiency of existing devices are common problems that urgently need to be solved in the industry. There is an urgent need to develop waste heat utilization devices that are simple in structure, do not require complex automation, and are highly efficient and low-cost, to recover waste heat for preheating lithium batteries and adapt to the development of green energy projects.

[0056] The following is combined Figure 1 The following describes embodiments of the present invention.

[0057] According to an embodiment of the present invention, in one aspect, an integrated temperature control system for lithium batteries based on waste heat recovery is provided, including a water cooling module, a waste heat recovery module, a preheating module, and a mode switching module. The water cooling module is configured to dissipate heat from the lithium battery pack 2 and output a cooling medium carrying waste heat. The waste heat recovery module is fluidly connected to the water cooling module and is configured to recover waste heat from the cooling medium. The preheating module is thermally connected to the waste heat recovery module and is configured to preheat the lithium battery pack 2 using the recovered waste heat. The mode switching module is disposed in the flow path between the water cooling module and the waste heat recovery module and is configured to operablely switch between a first state in which the cooling medium flows to the waste heat recovery module and a second state in which the cooling medium bypasses the waste heat recovery module.

[0058] According to a first embodiment of the present invention, an integrated temperature control system for lithium batteries based on waste heat recovery is provided. For example... Figure 1 As shown, the system mainly includes a water cooling module 100, a waste heat recovery module 200, a preheating module 300, and a mode switching module 400.

[0059] The water-cooling module 100 is used to dissipate heat from the lithium battery pack 2. During operation, this module circulates the cooling medium through the components that exchange heat with the lithium battery pack 2, thereby absorbing the heat generated during battery operation and outputting a cooling medium with increased temperature and carrying residual heat.

[0060] The waste heat recovery module 200 is fluidly connected to the outlet of the water-cooling module 100 via a pipeline. Its core function is to receive the cooling medium carrying waste heat flowing out of the water-cooling module 100, and to effectively extract and recover the waste heat carried in the cooling medium through a heat exchange process.

[0061] The preheating module 300 is connected to the waste heat recovery module 200 via heat transfer (i.e., thermal connection). This module is positioned around or in contact with the lithium battery pack 2 to receive the recovered heat from the waste heat recovery module 200 and directly use this heat to heat the lithium battery pack 2, thereby increasing the battery temperature in low-temperature environments.

[0062] The mode switching module 400 is installed in the fluid passage connecting the water-cooling module 100 and the waste heat recovery module 200. This module has a manual or automatic switching function, enabling it to switch between two different operating states.

[0063] First state: In this state, the cooling medium carrying waste heat flowing out of the water cooling module 100 is guided to the waste heat recovery module 200, thereby starting the waste heat recovery and battery preheating process.

[0064] Second state: In this state, the cooling medium flowing out of the water-cooling module 100 is guided to bypass (i.e., not through) the waste heat recovery module 200, and instead flows directly to the heat dissipation terminal (coolant tank 14) of the system. At this time, the system only performs the normal cooling and heat dissipation function.

[0065] Through the coordinated setup of the above four modules, the system in this embodiment achieves the goal of integrated temperature control management of the lithium battery pack 2 by flexibly switching between two working modes, "heat dissipation" and "waste heat recovery-preheating", within an integrated architecture.

[0066] In one embodiment, the mode switching module includes a manually operated valve 3.

[0067] The manual operating valve 3 is located in the fluid passage connecting the water-cooling module and the waste heat recovery module. The user can change the internal flow channel structure of the valve body by directly performing a physical operation on the manual operating valve 3 (e.g., rotating the handle or flipping the switch 6), thereby switching between two operating states.

[0068] When the manual operation valve 3 is operated to the first position, its internal flow channel is configured to the first state, that is, the passage from the water cooling module to the waste heat recovery module is opened.

[0069] When the manual operating valve 3 is operated to the second position, its internal flow channel is configured to the second state, that is, blocking the flow to the waste heat recovery module and allowing the cooling medium to bypass the module.

[0070] By employing a manually operated valve 3 as the actuator for mode switching, the system in this embodiment eliminates the need for complex electronically controlled sensors, controllers, and drive mechanisms, allowing for reliable switching of operating modes solely through direct user operation. This significantly simplifies the system structure and reduces manufacturing costs and potential failure rates.

[0071] In one embodiment, the water-cooling module includes a liquid cooling plate 12, a circulation pump 11, and an electric heater 13. The liquid cooling plate 12 is configured to be in thermal contact with the lithium battery pack 2. The circulation pump 11 drives the cooling medium to circulate between the liquid cooling plate 12 and a liquid storage container. The electric heater 13 is configured to provide auxiliary heating for the cooling medium.

[0072] The liquid cooling plate 12 is made of a metal material with good thermal conductivity and is configured to form a large area of ​​thermal contact with the surface of the lithium battery pack 2 in order to efficiently transfer the heat generated during battery operation.

[0073] The circulating pump 11 (e.g., a centrifugal pump or gear pump) serves as the driving core, with its inlet connected to the coolant tank 14 and its outlet connected to the inlet of the liquid cooling plate 12 via a pipeline. In the second state, when the circulating pump 11 is running, it drives the cooling medium to flow out of the coolant tank 14, pass through the liquid cooling plate 12 to absorb heat, and then return to the coolant tank 14, forming a complete forced circulation loop.

[0074] An electric heater 13 (such as a PTC heater or a resistance heating rod) is connected in series between the liquid cooling plate 12 and the circulating pump 11. Its core function is to start and provide auxiliary heating to the cooling medium in the circulation when the system determines that the recovered waste heat alone is insufficient to preheat the battery to the target temperature, thereby supplementing the heat source and ensuring the reliability of the battery preheating effect in low-temperature environments.

[0075] Through the coordinated arrangement of the liquid cooling plate 12, the circulating pump 11 and the electric heater 13, the water cooling module of this embodiment not only realizes the basic heat dissipation function of the lithium battery pack 2, but also has the ability to actively provide auxiliary heat source when necessary, thus forming a stable, reliable and more adaptable composite thermal management system together with the waste heat recovery module.

[0076] In one embodiment, the waste heat recovery module includes a plate heat exchanger 4 having a first flow channel and a second flow channel that are isolated from each other. The first flow channel is in fluid communication with the water-cooled module, and the second flow channel is filled with a preheating medium and is in fluid communication with the preheating module.

[0077] In this embodiment, the core component of the waste heat recovery module is a plate heat exchanger 4. The plate heat exchanger 4 is formed by stacking multiple corrugated metal plates sequentially, creating a series of parallel and isolated narrow flow channels between the plates. These flow channels are separated and combined into two independent fluid pathway systems: a first flow channel and a second flow channel.

[0078] The first flow channel is connected to the outlet of the water-cooled module via a pipeline. During system operation, the high-temperature cooling medium carrying waste heat output from the water-cooled module flows into this first flow channel.

[0079] The second flow channel is an independent closed loop filled with a preheating medium (such as antifreeze) specifically designed for heat transfer. This second flow channel is fluidly connected to the preheating module via another piping system.

[0080] When the high-temperature cooling medium flows through the first channel, its heat is transferred to the lower-temperature preheating medium in the adjacent second channel via metal plates. The two media flow in opposite directions or cross directions within their respective channels, achieving efficient heat exchange through the large heat exchange area of ​​the plates, thus transferring waste heat from the cooling medium to the preheating medium. Throughout the process, the cooling medium and the preheating medium remain physically isolated and do not mix, with heat conducted solely through the solid plates.

[0081] By using this plate heat exchanger 4 with isolated dual flow channels as the core of waste heat recovery, the module in this embodiment can extract waste heat from the water cooling system in a compact, efficient and reliable manner, and safely transport the recovered heat to the preheating module through an independent preheating medium loop.

[0082] In one embodiment, the preheating module includes a preheating cavity and a thermally conductive interface layer, wherein the preheating cavity covers at least a portion of the outer surface of the lithium battery pack 2; and the thermally conductive interface layer is disposed between the preheating cavity and the lithium battery pack 2.

[0083] The preheating chamber is a shell or enclosure structure with a specific shape, designed to accommodate and cover at least a portion of the outer surface of the lithium battery pack 2. The chamber has internal spaces or channels for the flow of working fluid carrying recovered heat from the waste heat recovery module, thus making it a centralized heat exchange area.

[0084] A thermally conductive interface layer is filled or disposed between the preheating cavity and the outer surface of the lithium battery pack 2. This layer is composed of a flexible or malleable material with a high thermal conductivity (e.g., a thermally conductive silicone pad, a thermally conductive phase change material, or a poured thermal paste). Its main function is to tightly adhere to both surfaces and fill the microscopic gaps generated during mechanical contact, thereby significantly reducing the contact thermal resistance from the preheating cavity to the surface of the lithium battery pack 2, thus ensuring that the recovered heat can be efficiently and uniformly transferred to the battery body.

[0085] By incorporating a preheating module that includes a preheating cavity and a thermally conductive interface layer, the system in this embodiment can concentrate the heat transferred from the waste heat recovery module onto the battery pack within a dedicated physical space. Furthermore, the optimized thermal interface efficiently transfers the heat into the battery, significantly improving the rate and uniformity of preheating the battery using waste heat in low-temperature environments. The preheating module also includes a heat storage container 5 located between the second flow channel and the preheating cavity, used to store the preheating medium flowing out of the plate heat exchanger 4 and as the working fluid flowing into the preheating cavity.

[0086] In one embodiment, the lithium battery integrated temperature control system based on waste heat recovery further includes a control unit, which is configured to:

[0087] Obtain the temperature information of lithium battery pack 2;

[0088] Based on temperature information, the control mode switching module switches states and / or controls the start and stop of the electric heater 13 in the water cooling module.

[0089] The control unit is the core of the system's logic processing, and its hardware foundation can be a smart switch containing a microprocessor, signal input interfaces, and drive output interfaces. This control unit is programmed to execute the following core control logic:

[0090] First, the control unit has PT100 thermal resistors installed in the lithium battery pack 2, the water outlet of the water cooling module, and the preheating chamber to obtain the temperature information of the lithium battery pack 2.

[0091] Secondly, the microprocessor of the control unit runs a preset control algorithm. This algorithm performs logical judgments based on temperature information and generates corresponding control commands:

[0092] When the temperature information indicates that the battery pack is in a low-temperature state and needs to be preheated, the control unit can output a command to switch the state of the control mode switching module, switching the valve from the "second state" of bypassing the waste heat recovery module to the "first state" of conducting the module.

[0093] Simultaneously or independently, when the algorithm determines that relying solely on the recovered waste heat may not be sufficient to meet the rapid preheating requirements, the control unit can output another command to control the start and stop of the electric heater 13 in the water cooling module, that is, to start the electric heater 13 to supplement the cooling medium with heat.

[0094] By introducing this control unit, the system in this embodiment achieves automated closed-loop control from temperature sensing to action execution. It can replace or assist manual operation, intelligently managing the working mode and the activation of auxiliary heat sources based on the actual temperature of the battery, thereby improving the system's responsiveness, ease of operation, and overall intelligence level of energy efficiency management.

[0095] In one embodiment, the control unit is further configured to:

[0096] Obtain the temperature information of the cooling medium output by the water-cooling module;

[0097] The conditions for the control mode switching module to switch to the first state include: the temperature of the lithium battery pack 2 is lower than the first preset threshold, and the temperature of the cooling medium is higher than the second preset threshold.

[0098] In this embodiment, in addition to being configured to acquire the temperature information of the lithium battery pack 2, the control unit is also specifically configured to acquire the temperature information of the cooling medium output by the water cooling module.

[0099] The control algorithm pre-set within the control unit thus has a richer basis for decision-making. Specifically, the algorithm defines the composite conditions that trigger the system to switch from the conventional heat dissipation mode to the waste heat recovery preheating mode.

[0100] The triggering condition includes two conditions that must be met simultaneously:

[0101] The temperature of lithium battery pack 2 is below a first preset threshold: This threshold (e.g., 0°C, 5°C, or 10°C) indicates that the battery is in a low-temperature state where performance is affected and preheating needs to be initiated.

[0102] The temperature of the cooling medium is higher than a second preset threshold: this threshold (e.g., 35°C, 40°C, or 45°C) indicates that the cooling medium discharged from the water-cooled module does indeed carry enough valuable residual heat for effective preheating.

[0103] Only when both of the above conditions are met will the control unit's logic output a command to drive the mode switching module to activate the waste heat recovery and preheating process. If only the battery temperature is low but the cooling medium temperature is also low (insufficient waste heat), or if the cooling medium temperature is high but the battery temperature is already within a suitable range, the control unit will not trigger mode switching, thus avoiding ineffective or redundant waste heat recovery operations and achieving more precise and energy-saving intelligent control.

[0104] In one embodiment, the lithium battery integrated temperature control system based on waste heat recovery further includes an optimization unit communicatively connected to the control unit, the optimization unit being configured to:

[0105] Based on the operating parameters and / or environmental parameters of lithium battery pack 2, an optimized instruction for adjusting the operating parameters of the water cooling module and / or waste heat recovery module is output through a pre-trained neural network model.

[0106] The operating parameters include at least one of the following: the flow rate of the circulating pump 11, the power of the electric heater 13, and the operating parameters of the plate heat exchanger 4.

[0107] An optimization unit is a hardware module (such as a computing board with a dedicated AI chip) or software function module with data analysis and model calculation capabilities. It communicates with the control unit via a wired or wireless communication bus, forming information exchange and command coordination.

[0108] This optimization unit is configured to perform advanced energy efficiency optimization tasks, and its workflow and functions are as follows:

[0109] First, it continuously or periodically obtains the operating parameters (such as the current charge / discharge rate, temperature difference within the battery pack) and / or environmental parameters (such as ambient temperature) of the lithium battery pack 2 as input from the control unit or other sensors in the system.

[0110] Secondly, its core lies in the built-in pre-trained neural network model. Upon receiving real-time input parameters, the optimization unit calls this model to perform calculations and ultimately outputs optimization instructions for adjusting the operating parameters of the water-cooling module and / or waste heat recovery module. These instructions are then sent to the control unit via a communication link, which in turn drives the corresponding actuators to make adjustments.

[0111] The operating parameters to be optimized are an adjustable set that includes at least one of the following three:

[0112] The flow rate of the circulating pump 11 is adjusted by changing the pump speed to change the cooling intensity.

[0113] The power of the electric heater 13 is controlled by adjusting the duty cycle or voltage to control the heating intensity.

[0114] The operating parameters of plate heat exchanger 4, for example, can be adjusted by changing the flow rate of the preheating medium flowing through the heat exchanger by adjusting the opening of the bypass valve.

[0115] According to an embodiment of the present invention, in another aspect, a lithium battery thermal management method is also provided, comprising:

[0116] The lithium battery pack 2 is cooled by a water-cooling module, which generates a cooling medium that carries the residual heat.

[0117] Monitor the temperature of lithium battery pack 2;

[0118] When the temperature of lithium battery pack 2 is lower than the preheating trigger temperature, the control mode switching module switches to the first state, guides the cooling medium to the waste heat recovery module to recover waste heat, and uses the recovered waste heat to preheat lithium battery pack 2.

[0119] When the recovered waste heat is insufficient to raise the temperature of the lithium battery pack 2 to the target temperature, the electric heater 13 in the water cooling module is activated to provide auxiliary heating for the cooling medium.

[0120] This method is executed in the following logical sequence:

[0121] Step 1: Basic heat dissipation and waste heat generation

[0122] First, the system operates its water-cooling module, which uses a circulating cooling medium to forcibly dissipate heat from the lithium battery pack 2, which is in operation. During this process, the cooling medium absorbs the heat generated by the battery, causing its own temperature to rise, thus becoming a cooling medium that carries away excess heat. This step is the normal operating procedure of the system, ensuring the temperature safety of the battery under normal working load.

[0123] Step 2: Battery Temperature Status Monitoring

[0124] The system continuously or periodically monitors the temperature of lithium battery pack 2.

[0125] Step 3: Waste Heat Recovery and Preheating Trigger

[0126] The control unit compares the monitored battery temperature with a preset preheating trigger temperature (e.g., 5°C or 10°C). When the temperature of lithium battery pack 2 is lower than this preheating trigger temperature, it is determined that the battery is in a low-temperature state requiring preheating. At this time, the control unit generates a command, and the control mode switching module switches to the first state. In this state, the cooling medium carrying residual heat flowing from the water cooling module is redirected and guided to the waste heat recovery module. The waste heat recovery module extracts heat from the cooling medium and transfers the recovered waste heat to the preheating module, ultimately preheating the lithium battery pack 2 and increasing its temperature to improve electrochemical performance.

[0127] Step 4: Auxiliary Heating Guarantee

[0128] During the preheating process, the system continuously evaluates the preheating effect. When the recovered waste heat is insufficient to raise the temperature of the lithium battery pack 2 to the preset target temperature (e.g., in extremely low temperature environments or when the waste heat is very small), the system determines that the waste heat is insufficient. To ensure that the preheating target is achieved, the control unit will activate the electric heater 13 in the water-cooling module. This electric heater 13 provides auxiliary heating to the circulating cooling medium, artificially raising its temperature, thereby providing an additional, stable heat source for the battery through the waste heat recovery loop until the battery temperature reaches the target range.

[0129] The method provided in this embodiment creatively integrates conventional heat dissipation, waste heat recovery, battery preheating, and active heat replenishment through the closed-loop execution of the above four steps. Its core advantage lies in prioritizing and maximizing the utilization of the waste heat energy generated by the system itself, consuming only a small amount of electrical energy for replenishment when necessary. This completely solves the problem of low-temperature performance degradation of lithium batteries while significantly reducing the high energy consumption of traditional pure electric heating solutions, achieving a balance between high efficiency and low energy consumption. It is particularly suitable for green application scenarios with stringent energy efficiency requirements, such as new energy vehicles and energy storage power stations.

[0130] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A lithium battery integrated temperature control system based on waste heat recovery, characterized in that, The application comprises: a water cooling module configured to dissipate heat from a lithium battery pack (2) and output a cooling medium carrying residual heat; a residual heat recovery module in fluid communication with the water cooling module and configured to recover residual heat from the cooling medium; a preheating module in thermal communication with the residual heat recovery module and configured to preheat the lithium battery pack (2) using the recovered residual heat; and a mode switching module disposed on a flow path between the water cooling module and the residual heat recovery module and configured to be operable to switch between a first state in which the cooling medium flows to the residual heat recovery module and a second state in which the cooling medium bypasses the residual heat recovery module. The mode switching module comprises a manually operated valve (3).

2. The waste heat recovery based integrated temperature control system for lithium battery of claim 1, wherein, The water cooling module comprises:

3. The waste heat recovery based integrated temperature control system for lithium battery of claim 1, wherein, a liquid cooling plate (12) configured to be in thermal contact with the lithium battery pack (2); a circulating pump (11) configured to drive the circulation of the cooling medium between the liquid cooling plate (12) and a liquid storage container; and an electric heater (13) configured to assist in heating the cooling medium. The residual heat recovery module comprises a plate heat exchanger (4) having a first flow channel and a second flow channel isolated from each other, the first flow channel being in fluid communication with the water cooling module, and the second flow channel being filled with a preheating medium and being in fluid communication with the preheating module.

4. The waste heat recovery based integrated temperature control system for lithium battery of claim 3, wherein, The preheating module comprises:

5. The waste heat recovery based integrated temperature control system for lithium battery of claim 4, wherein, a preheating cavity covering at least part of the outer surface of the lithium battery pack (2); and a thermally conductive interface layer disposed between the preheating cavity and the lithium battery pack (2). A heat storage container (5) is further disposed between the second flow channel and the preheating cavity.

6. The waste heat recovery based integrated temperature control system for lithium battery according to claim 5, wherein, A control unit is further provided, which is configured to:

7. The waste heat recovery based integrated thermal control system for lithium battery of claim 4, wherein, obtain temperature information of the lithium battery pack (2); based on the temperature information, control the state switching of the mode switching module and / or control the start / stop of the electric heater (13) in the water cooling module. The control unit is further configured to:

8. The waste heat recovery based integrated temperature control system for lithium battery of claim 7, wherein, obtain temperature information of the cooling medium output by the water cooling module; wherein the condition for controlling the mode switching module to switch to the first state comprises that the temperature of the lithium battery pack (2) is lower than a first preset threshold and the temperature of the cooling medium is higher than a second preset threshold. An optimization unit in communication connection with the control unit is further provided, which is configured to: 9.The waste heat recovery based integrated temperature control system of lithium battery according to claim 7, wherein, based on the working condition parameters and / or environmental parameters of the lithium battery pack (2), output an optimization instruction for adjusting the operating parameters of the water cooling module and / or the residual heat recovery module through a pre-trained neural network model; the operating parameters include at least one of the flow rate of the circulating pump (11), the power of the electric heater (13), and the operating parameters of the plate heat exchanger (4). The application comprises:

10. A method of thermal management of a lithium battery, characterized in that, dissipating heat from a lithium battery pack (2) through a water cooling module to generate a cooling medium carrying residual heat; monitoring the temperature of the lithium battery pack (2); ​ When the temperature of the lithium battery pack (2) is lower than a preheating trigger temperature, the control mode switching module switches to a first state, guides the cooling medium to the waste heat recovery module to recover waste heat, and preheats the lithium battery pack (2) by using the recovered waste heat; When the temperature of the lithium battery pack (2) cannot be raised to a target temperature by the recovered waste heat, the electric heater (13) in the water cooling module is started to assist in heating the cooling medium.

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